China Meteorological Disaster Dictionary: Zhejiang Volume

Author: Editorial Committee of the "Comprehensive Catalog of China's Meteorological Disasters"
Publisher:
Publishing Date: 2006-11-01
Features: Zhejiang Province is located in the southeastern coastal area of China and belongs to a typical subtropical monsoon climate. In winter, under the control of the Mongolian cold high-pressure system, northwesterly winds prevail, with clear, cold, and dry weather being the norm. It is a season of low temperatures and little rainfall, with cold waves, heavy snow, strong winds, and severe icing being the main disaster-prone weather conditions. In summer, under the control of the Pacific subtropical high-pressure system, southeasterly winds dominate, bringing abundant moisture from the ocean, resulting in humid air and a season of high temperatures and strong sunlight. In early summer, cold and warm air masses often converge in the province's airspace, leading to the season, where heavy rain and flood disasters frequently occur. In midsummer, it is a period of high temperatures and drought, with drought and typhoons being the main disaster-prone weather conditions. Spring and autumn are transitional seasons between winter and summer. In spring, cyclone activity is frequent, with abundant precipitation and significant temperature fluctuations, earning the saying "children's faces in spring change three times a day." Low temperatures, continuous drizzle, hail, and heavy rain are the main disaster-prone weather conditions. In autumn, the climate is generally mild and rainy, with the saying "autumn sky is high and weather is clear." Drought, typhoons, and autumn cold are the main disaster-prone weather conditions. Due to the small stability of the monsoon, the varying intensity and timing of the winter and summer monsoons each year lead to abnormal low and high temperatures, or irregular rainfall, causing droughts and floods. Moreover, since Zhejiang is located in a transitional zone between the middle and low latitudes and at the junction of the Jiangnan mountainous region and the Yangtze River Delta plain, with both land and sea nearby, it is affected by both the Siberian cold currents from the west and the tropical systems from the ocean. As a result, the province experiences frequent and numerous disaster-prone weather conditions throughout the year, including typhoons, heavy rain, floods, droughts, cold waves, heavy snow, strong winds, and hail, all of which bring severe disasters to Zhejiang. The rivers in Zhejiang Province have short sources, rapid flow rates, and significant drops, making it difficult to store water. During dry periods, droughts are prone to occur. The lower reaches of the rivers directly flow into the sea and are often blocked by tidal surges. During rainy periods, due to poor drainage, floods and disasters are easily caused. The terrain in Zhejiang is high in the southwest and low in the northeast. The mountain ranges run perpendicular or at an oblique angle to the direction of the monsoon circulation, providing a certain barrier effect against the cold currents from the north and the typhoons from the southeast. However, when typhoons strike, the mountains slow down their movement and block the airflow, causing it to rise and intensify rainfall, further exacerbating the strong winds and flood disasters in the coastal areas caused by typhoons. Additionally, after landing, typhoons often turn northeast or